Third-person games can work very well with a keyboard and mouse setup.Complaining about mouse support is like people who complain bout no mouse suppprt in dybasty warrior ports.
These type of games will never work brilliantly on a mouse n keyboard due to the nature of movement and combat.
Id never dream of playing a game like thia bayonetta etc on mouse n keyboard it would be handicapping yourself for no reason. Saying its a bad port because of that is just silly
I don't know why you would think that they should only be playable with a controller.
Keyboard & Mouse is not my preferred way to play a character action game like Nier, but I hope that someone fixes the aiming acceleration because it makes the game borderline unplayable with mouse, touchpad, or gyro aiming in my opinion.
I'm having to play this using a DualShock 4 instead of my Steam Controller or KB&M, which would be my preferred options. I hate dual-analog controls.